Testing Procedures

Standard microbiological swab and air samples were taken throughout both wings. These tests were scheduled on a rotating basis so that each item and location tested on the treated wing had a corresponding test site on the control wing. Both tests were conducted on the same day and as close as possible in time. Over the 18-month test period, each site was tested approximately every two weeks. There were 45 surface and 10 air sites sampled on each wing, for a total of 110 data point locations. Each week, specific sites were tested. These were rotated on a two-week schedule throughout the 18- month test period.

Surface samples were taken using standard microbiological swabs, covering four square inches (2581 mm2) and using standard culturing protocols. The results were reported in terms of the total number of colony forming units (cfu) of microorganisms appearing on the agar plates following the incubation period. Air samples were taken using a standard Anderson air sampler. These results were recorded in cfu per cubic foot of air sampled. Although each site on each wing was monitored over the entire test period, only average values for all sites within a wing, for any one period, were used for comparison. For example, at six months the average of the 10 air samples taken in the treated wing at that time, were averaged and compared to the average of the corresponding 10 sites in the control wing. This provided a single value that represented the entire wing, even though the distribution of values within the wing may differ somewhat from month to month. The same comparison of average values was made for the surface swab tests.